The disclosed technology relates to compositions containing a quaternary ammonium salt for metal-working and/or hydraulic fluids having improved water separation. In a particular embodiment, the technology relates to corrosion-preventative or rust-preventive coating compositions and methods of their use. Such coating compositions comprise a rust preventative composition, optionally including a diluent, and a quaternary ammonium salt.
A majority of rust preventives (RPs) are based on slack waxes generated from Group I refineries. Natural waxes provide an alternative to Group I slack waxes in rust preventives, and natural wax-based RPs can offer improved salt spray protection, among other features. However, the applications for natural wax-based RPs are limited by their poor ability to separate water. Good water separation is a necessary feature for RPs which are applied in dip tanks, to prevent the solvent-based RP from becoming diluted by carryover water from previous washing or machining processes.
There is a need to find additives that can be used to improve the water separation properties of metal working fluids as well as hydraulic fluids without compromising other key performance factors. As previously mentioned, new experimental formulations based on natural waxes suffer from poor water separation properties, but commercially available RPs, have similar issues with water separation.